Đáp án:
Giải thích các bước giải:
`a.`
`Fe+2HCl->FeCl_2+H_2↑`
`Zn+2HCl->ZnCl_2+H_2↑`
`b.`
`n_{HCl}=0,3.2=0,6(mol)`
`n_{H_2}=\frac{4,48}{22,4}=0,2(mol)`
Gọi `a,b,c` là `n_{Fe},n_{Zn},n_{CuO}`
`m_{hh}=56a+65b+80c=20,1(1)`
`CuO+2HCl->CuCl_2+H_2O`
`∑n_{HCl}=2a+2b+2c=0,6(2)`
`∑n_{H_2}=a+b=0,2(3)`
`(1),(2),(3)=>a=0,1;b=0,1;c=0,1`
`%m_{Fe}=\frac{0,1.56}{20,1}.100=27,86%`
`%m_{Zn}=\frac{0,1.65}{20,1}.100=32,34%`
`%m_{CuO}=\frac{0,1.80}{20,1}.100=39,8%`
`#Devil`